<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>字体样式标签</title>
    <style>
        body{
            font-size: 8em;
        }
    </style>
</head>
<body>
    <i>斜体</i><br>
    <b>加粗</b><br>
    <em>斜体</em><br>
    <u>下划线</u>

</body>
</html>